The invention is an improvement and extension of the EEG Biofeedback Method and System for Training Voluntary Control of Human EEG Activity as set forth in U.S. Pat. No. 4,928,704, which is fully incorporated by reference into this application. Biofeedback information can be used to foster rapid learning of self-control using electroencephalography (EEG). The invention covered in the '704 patent encompasses an EEG biofeedback apparatus for providing simultaneous, minimal phase delay feedback on multiple sub-bands of EEG filtered out of multiple independent EEG channels.
The most common purpose of biofeedback in general, and EEG biofeedback in particular, is to permit an individual to use the feedback information to learn a useful degree of voluntary self-control of a specific biofeedback parameter. Each of the major sub-bands of the EEG (alpha, beta, delta, gamma, theta) has unique bio-electric characteristics which correspond with unique subjective characteristics within the experience of the individual. Alpha is associated with a variety of wakeful states involving creativity, calming of the mind, and inner focus of awareness, beta is associated with alert wakeful situations with external focus as well as with stress and anxiety, delta is associated most clearly with coma and deep sleep, and theta is associated with light sleep and drowsiness. Gamma have not received as much attention from researchers but is associated with precognition and high-level information processing. Recently Buddhist meditators practicing “compassion meditation” showed big increases in Gamma EEG activity that were positively correlated with the number of 1,000s of hours of practice of this compassion meditation.
The use of simultaneous, minimal phase delay EEG biofeedback has been found to increase the likelihood of psychological benefits to trainees including enhanced serenity, deeper understandings, and relief from anxiety and depression. However, some trainees do not have much naturally-occurring activity (e.g., low amplitude and low abundance) in a particular brain wave band such as alpha or theta. This situation can present an impediment to the rate of improvement of self control experienced by such trainees. There is a need for a method that can enhance the biofeedback provided by the EEG biofeedback system in a way that instantaneously follows the brain's naturally-occurring frequencies of peak energy in a desired band or sub-band and that does not impose a peak energy at a non-naturally-occurring frequency. In addition, most trainees using prior art biofeedback systems benefit most when they focus attention on the one or two channels with the greatest amplitudes. In this context, the other weaker channels tend to follow along and do better than if the trainee has focused attention during the neurofeedback only on the weaker channels. Thus, there is also a need for a way to facilitate the ability for trainees to boost activity in weaker channels in a manner that avoids unnatural entrainment of brain wave frequency.